After beating Blane on Cinnabar Island, just walk outside and Bill will take you to One Island. After he takes you into the Pokemon center, he'll ask you to do him a favor and give you the tri-pass.
The rainbow pass is a key item in Pokemon FireRed version. To trigger the events to get it, you first need to own 60 different Pokemon.
beat the elite 4
The Rainbow Badge
you need a ticket not a rainbow or tri
if you mean rainbow badge go down cycling road and vs koga
beat the elite four then talk to celio on island 1
You have to get the ruby and give it to celio. He will then give you a rainbow pass
you have to find the ruby in mt ember and bring it to celio but first you need the national pokedex--Check this answer out: http://wiki.answers.com/Q/How_do_you_unlock_islands_after_beating_the_elite_four
You must beat the seven gym leaders, the elite four, and your rival. Then you have to capture 60 Pokemon to get your Rainbow pass the will allow you to travel to Island 7 in Pokemon FireRed.
u cant unless you get the special event tickets
You don't. It only goes up to seven, I think.
Talk to Celio on One Island. (I think you have to beat the Elite Four first)